1. Field of Invention
The invention relates to a shredder and, in particular, to a shredder with a shredding blade set with different combinations of pressed blades and polished blades. It provides an appropriate friction for solving the problems with tilted or wrinkled paper due to insufficient friction or power waste due to large friction.
2. Related Art
As shown in FIGS. 1 and 2, the outer parts of shredder cutting blades are often polished or pressed, respectively. During the shredding process, the former in FIG. 1 has a smaller friction. Therefore, paper is likely to be tilted or wrinkled. To solve this problem, the winding angle of the polished cutting blades of FIG. 1 has to be increased in order to increase the friction. Nonetheless, the power of the motor has to increase correspondingly. This not only increases the costs for motor components, the power consumption rises as well. For the pressed cutting blades as shown in FIG. 2, the friction thereof is too large during the shredding process. Thus, even though it solves the problem with tilted or wrinkled paper, it still needs a powerful motor to provide a sufficiently strong driving force. The problem with high power consumption still exists.